Oilbird
Encyclopedia
The Oilbird also known as Guácharo, is a bird found in the northern areas of South America
(including the island of Trinidad
in the Republic of Trinidad and Tobago). They are nocturnal feeders on the fruits of the Oil Palm
and tropical laurel
s, and are the only nocturnal fruit eating birds in the world. They forage at night, navigating by echolocation
in the same way as bat
s, but with a high-pitched clicking sound audible to humans.
s and usually placed with these in the order
Caprimulgiformes
. However, the nightjars and their relatives are insectivore
s while the Oilbird is a specialist fructivore, and it is sufficiently distinctive to be placed in a family (Steatornithidae) and suborder (Steatornithes) of its own. Some research indicates that it should even be considered a distinct order (which does not yet have a valid taxonomic name).
The caripensis of the binomial name means "of Caripe", and Steatornis means "fat bird", in reference to the fatness of the squabs. The oilbird is called a "guácharo" or "tayo" in Spanish
, both terms being of indigenous origin. In Trinidad it was sometimes called "diablotin" (French for "little devil"), presumably referring to its loud cries, which have been likened to those of tortured men. The common name of the "Oilbird" comes from a grim origin: the fact that in the past chicks were captured and boiled down in order to make oil.
and the island of Trinidad
to Venezuela
, Colombia
, Ecuador
, Peru
and Bolivia
in forests and woodlands with caves. It is a seasonal migrant
, moving from its breeding caves in search of fruit trees. It has occurred as a rare vagrant to Costa Rica
, Panama
and Aruba
. The Guácharo Cave
(Oilbird Cave), in the mountainous Caripe
district of northern Monagas
, Venezuela
, is where Alexander von Humboldt
first studied the species.
in sufficiently poor light conditions, using a series of sharp audible clicks for this purpose. It also produces a variety of harsh screams while in its caves. Entering a cave with a light especially provokes these raucous calls; they also may be heard as the birds prepare to emerge from a cave at dusk.
cave nesters. The nest is a heap of droppings, usually above water - either a stream or the sea, on which 2-4 glossy white eggs are laid which soon become stained brown. These are rounded but with a distinctly pointed smaller end and average 41.2 X 33.2 mm. The squabs become very fat before fledging, weighing up to half again as much as the adult birds do. They used to be harvested and rendered for oil, hence the name "oilbird".
also has a national park named after its "Cueva de los Guácharos
", near the southern border with Ecuador. Oilbirds have been reported in various other places along the Andean
mountain chain, including near Ecuador's Cueva de los Tayos
and in Brazil
: they are known to dwell as far south as the Carrasco National Park in Bolivia
. Dunston Cave
, at the Asa Wright Nature Centre
in Trinidad
, is home to about 200 nesting pairs.
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
(including the island of Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
in the Republic of Trinidad and Tobago). They are nocturnal feeders on the fruits of the Oil Palm
Oil palm
The oil palms comprise two species of the Arecaceae, or palm family. They are used in commercial agriculture in the production of palm oil. The African Oil Palm Elaeis guineensis is native to West Africa, occurring between Angola and Gambia, while the American Oil Palm Elaeis oleifera is native to...
and tropical laurel
Lauraceae
The Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 3500, perhaps as many as 4000, species world-wide, mostly from warm or tropical regions, especially Southeast Asia and South America...
s, and are the only nocturnal fruit eating birds in the world. They forage at night, navigating by echolocation
Animal echolocation
Echolocation, also called biosonar, is the biological sonar used by several kinds of animals.Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects...
in the same way as bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s, but with a high-pitched clicking sound audible to humans.
Description
This is a large, slim bird at 41–49 cm (16-19"), with a wing span of 95 cm (just over 3 ft). It has a flattened, powerfully hooked, bill surrounded by deep chestnut rictal bristles up to 5 cm (2") long. Adults weigh 375-455 grams (13.2-16 oz) but the chicks can weigh considerably more, at up to 600 grams (1.3 lbs), when their parents feed them a good deal of fruit before they fly. It is mainly reddish-brown with white spots on the nape and wings. Lower parts are cinnamon-buff spotted with white. The stiff tail feathers are a rich brown spotted with white on either side. The feet are small and almost useless, other than for clinging to vertical surfaces. The long wings make it capable of hovering and twisting flight, which enables it to navigate through restricted areas of its caves.Taxonomy and etymology
Oilbirds are related to the nightjarNightjar
Nightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
s and usually placed with these in the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Caprimulgiformes
Caprimulgiformes
The Caprimulgiformes is an order of birds that includes a number of birds with global distribution . They are generally insectivorous and nocturnal...
. However, the nightjars and their relatives are insectivore
Insectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....
s while the Oilbird is a specialist fructivore, and it is sufficiently distinctive to be placed in a family (Steatornithidae) and suborder (Steatornithes) of its own. Some research indicates that it should even be considered a distinct order (which does not yet have a valid taxonomic name).
The caripensis of the binomial name means "of Caripe", and Steatornis means "fat bird", in reference to the fatness of the squabs. The oilbird is called a "guácharo" or "tayo" in Spanish
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...
, both terms being of indigenous origin. In Trinidad it was sometimes called "diablotin" (French for "little devil"), presumably referring to its loud cries, which have been likened to those of tortured men. The common name of the "Oilbird" comes from a grim origin: the fact that in the past chicks were captured and boiled down in order to make oil.
Distribution and habitat
The Oilbird ranges from GuyanaGuyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
and the island of Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
to Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
and Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
in forests and woodlands with caves. It is a seasonal migrant
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, moving from its breeding caves in search of fruit trees. It has occurred as a rare vagrant to Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
and Aruba
Aruba
Aruba is a 33 km-long island of the Lesser Antilles in the southern Caribbean Sea, located 27 km north of the coast of Venezuela and 130 km east of Guajira Peninsula...
. The Guácharo Cave
Cueva del Guácharo National Park
The Guácharo Cave National Park is located 12 km from the town of Caripe, Monagas, Venezuela. It has as its centerpiece a large limestone cave, which is home to thousands of oilbirds...
(Oilbird Cave), in the mountainous Caripe
Caripe
Caripe is a town in Caripe Municipality in the mountainous north of the state of Monagas in eastern Venezuela.The soil of the Caripe Valley is very fertile, and the climate of the area is exceptionally pleasant, a result of its altitude , latitude , and proximity to the Caribbean Sea...
district of northern Monagas
Monagas
Monagas State is one of the 23 states of Venezuela.Monagas State covers a total surface area of 28,900 km² and, in June 30, 2010, had an estimated population of 908,626....
, Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
, is where Alexander von Humboldt
Alexander von Humboldt
Friedrich Wilhelm Heinrich Alexander Freiherr von Humboldt was a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher and linguist Wilhelm von Humboldt...
first studied the species.
Behaviour
Oilbirds are nocturnal; during the day the birds rest on cave ledges and leave to find their food at night. Although it forages by sight, the Oilbird is one of only a few birds, and the only nocturnal one, known to navigate by echolocationAnimal echolocation
Echolocation, also called biosonar, is the biological sonar used by several kinds of animals.Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects...
in sufficiently poor light conditions, using a series of sharp audible clicks for this purpose. It also produces a variety of harsh screams while in its caves. Entering a cave with a light especially provokes these raucous calls; they also may be heard as the birds prepare to emerge from a cave at dusk.
Breeding
Oilbirds are colonialBird colony
A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony...
cave nesters. The nest is a heap of droppings, usually above water - either a stream or the sea, on which 2-4 glossy white eggs are laid which soon become stained brown. These are rounded but with a distinctly pointed smaller end and average 41.2 X 33.2 mm. The squabs become very fat before fledging, weighing up to half again as much as the adult birds do. They used to be harvested and rendered for oil, hence the name "oilbird".
Status and conservation
The Guácharo Cave was Venezuela's first national monument, and is the centerpiece of a national park; according to some estimates there may be 15,000 or more birds living there. ColombiaColombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
also has a national park named after its "Cueva de los Guácharos
Cueva de los Guácharos
The Cueva de los Guácharos National Park , created in 1960, is the oldest of the 51 protected areas of Colombia. The park is located in the western face of the Colombian Eastern Andean Range in the departments of Huila and Caquetá...
", near the southern border with Ecuador. Oilbirds have been reported in various other places along the Andean
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
mountain chain, including near Ecuador's Cueva de los Tayos
Cueva de los Tayos
Cueva de los Tayos is a natural cave located on the eastern slopes of the Andes mountains in the Morona-Santiago province of Ecuador...
and in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
: they are known to dwell as far south as the Carrasco National Park in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
. Dunston Cave
Dunston Cave
Dunston Cave is a igneous cave on the Northern Range of Trinidad and Tobago. The cave is located on the grounds of the Asa Wright Nature Centre. Originally named Guacharo Cave, it was renamed Dunston Cave in 1972 in honour of engineer John Dunston. The caves are home to an Oilbird colony. These...
, at the Asa Wright Nature Centre
Asa Wright Nature Centre
The Asa Wright Nature Centre and Lodge is a nature resort and scientific research station in the Arima Valley of the Northern Range in Trinidad and Tobago. The Centre is one of the top birdwatching spots in the Caribbean; a total of 159 species of birds have been recorded there...
in Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
, is home to about 200 nesting pairs.
External links
- Cueva del Guácharo (ShowCaves)
- Oilbird videos, photos & sounds on the Internet Bird Collection
- The oilbird's visual acuity.
- Oilbird sounds on xeno-canto.org Caripe.net - La Puerta de Entrada
- Oilbird Caves of Trinidad Accessed 30 March 2011